Rusty stains on one backing plate

[GMH]

Any idea what might cause this? It is only on one backing plate. I have driven in the rain, but no puddles or deep water. I have recently had the bearings re-packed and the springs replaced.

[chuckster57]

That’s rusty water from inside the axle. Look at where the brake wires come out. If your trailer is still in warranty, I would send some pics to your dealer.

[GMH]

That’s possible, but why wouldn’t it be on both sides? There are holes for the wires on both sides. It is also 11 years old and has never been through any deep water.

[chuckster57]

I don’t have an answer for that.

[JRTJH]

On a 2010 trailer, I'd guess the axles are either Al Ko or Dexter. There should be a tag on the axle beam that identifies the manufacturer and the model number/serial number of the axles. I'd send those photos to the axle manufacturer and ask them for recommendations....

My concern, if it were my trailer, is that the inside of the axle beam may be corroded. If it is, the extent of corrosion may be insignificant, or it may be bad enough to degrade the axle integrity.

Why it happened is anybody's guess, it could be something like a cracked axle beam, a bad weld on the brake backing plate that burned through the axle tube, it could be a plugged drain hole that allowed the beam to fill with water until it reached the "top hole and is weeping out... If the axle tube is filled with water for "several years", did the freeze/thaw cycles damage the axle beam?

With your statement that you just had the springs replaced, it could be something as simple as a piece of tin between two springs that's rusting and should be removed. If so, then it's probably of no consequence. But until you know for sure......

Lots of questions that I'd want answers to before setting off on a cross country trip..... Or, for that matter, before getting on a busy interstate at 70MPH.....

[jasin1]

Originally Posted by GMH

That’s possible, but why wouldn’t it be on both sides? There are holes for the wires on both sides. It is also 11 years old and has never been through any deep water.

Is that the heavy side of your trailer? Or where you store it that may be the low side when it’s parked..water has to drain from one side or the other.
You would probably never have the axle perfect level while parked even though the trailer may be level.
It could be condensation forming inside the axle while in storage…wonder if the drain holes are clogged on one side or something inside trapping water and making it drain slowly

[GMH]

Originally Posted by JRTJH

On a 2010 trailer, I'd guess the axles are either Al Ko or Dexter. There should be a tag on the axle beam that identifies the manufacturer and the model number/serial number of the axles. I'd send those photos to the axle manufacturer and ask them for recommendations....

My concern, if it were my trailer, is that the inside of the axle beam may be corroded. If it is, the extent of corrosion may be insignificant, or it may be bad enough to degrade the axle integrity.

Why it happened is anybody's guess, it could be something like a cracked axle beam, a bad weld on the brake backing plate that burned through the axle tube, it could be a plugged drain hole that allowed the beam to fill with water until it reached the "top hole and is weeping out... If the axle tube is filled with water for "several years", did the freeze/thaw cycles damage the axle beam?

With your statement that you just had the springs replaced, it could be something as simple as a piece of tin between two springs that's rusting and should be removed. If so, then it's probably of no consequence. But until you know for sure......

Lots of questions that I'd want answers to before setting off on a cross country trip..... Or, for that matter, before getting on a busy interstate at 70MPH.....

It is a Dexter axle. The only holes in the axle tube are where the wires enter (no drain holes). I rapped on both axles with a ball peen hammer and they sound the same….as in sound. I think there must have been some water in the tube and when they had the axles off to do the springs, it rolled 90 degrees so it ran out where the wires are?
I can’t imagine how very much water could get in. We did get 6” of rain in two hours while camped just prior to getting the springs done. I suppose maybe it could have run down the wires and in? The spring shop said to bring it back and they would pull the bakes off that side and inspect it free of charge.